I tried both your Flash sites and only get a problem with Transformice if Adblock Plus is enabled. If you have that installed, click the arrow to the right of the Adblock Plus button on the Firefox toolbar and choose "Disable on Transformice". See screenshot.

As regards the other site, I was able to play a video without a problem even with Adblock Plus enabled.

If you right click the player on Justin TV, does it show which version of Flash you have installed as shown in the screenshot?

Also, if you right click the Windows Taskbar, go to Task Manager and then click the "Processes" tab, can you see "plugin_container.exe" running? You need to check for it when you load a Flash player somewhere.

If you right click the player on Justin TV, does it show which version of Flash you have installed as shown in the screenshot?

Yes, I have the 10.3.

Also, if you right click the Windows Taskbar, go to Task Manager and then click the "Processes" tab, can you see "plugin_container.exe" running? You need to check for it when you load a Flash player somewhere.

If you have several sites open and then decide to view a video somewhere, but due to a problem with it, it crashes, without the plugin_container.exe process running, the whole browser would crash. The plugin_container runs like a kind of sandbox if you like which isolates a video from the rest of the browser so that if it crashes, you can still carry on using Firefox. So if you end task on that process, then videos can no longer play.

By the way, you should update Flash to the latest version which is 11.1.102.55, download from: http://get.adobe.com/flashplayer/ The version you're using at the moment is a security risk and exposes your PC to attack.

No. ActiveX is a Microsoft technology and not supported in Firefox. You only need the ActiveX version if you use Internet Explorer.

Could you try starting Firefox in Safe Mode and see if that makes any difference. To do that, click "Help", then "Restart with add-ons disabled". Firefox will close and then you'll see a menu. Don't checkmark any of the boxes; just click the button called "Continue in Safe Mode". Firefox will subsequently restart with all your add-ons disabled.

Next, go to both sites and see if it makes any difference. If the videos play properly, then one of your Add-ons is causing the problem. What you would need to do in that particular case is to repeat the same steps, then when you see the menu, checkmark the top option called "Disable all add-ons". After Firefox restarts, start re-enabling your add-ons one-by-one until the problem recurs. Then you'll know which one it is which is causing the problem.

Do you have a parent who may have installed filtering software and has blocked those two sites to prevent you from accessing them? Maybe you're of school age and spend too much time on the PC instead of doing your homework for example.

I doubt if Adobe is at fault because if it was, then many more users would be experiencing the same problem as you. But as you can see from the following screenshot, I can play Transformice without a problem. Incidentally, it reminds me a bit of an old game I used to play called "Lemmings".